220 research outputs found

    Texture analysis in an apple progeny through instrumental, sensory and histological phenotyping

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    Phenotypic analysis of texture traits was performed in an apple progeny by three complementary approaches: two classical instrumental measurements (compression and penetrometry), sensory assessment and histological screening. The progeny was composed of 141 individuals harvested over 2 years. Sensory and instrumental texture were assessed at harvest and after 2 and 4 months of cold storage. Histological screening was performed by combining macro-vision of outer parenchyma sections and image analysis on fruits after 2 months storage. Harvest year was observed to have a major impact on texture phenotypes followed by storage and genetic factors. Principal component analysis of data from the instrumental texture evaluations showed that the two methods complemented each other in characterizing the texture of the apple progeny. Compression parameters correlated better than penetrometry variables with sensory descriptors related to crispness, firmness, and graininess. Cell size distribution differentiated individuals in the apple progeny. It correlated with instrumental texture analyses and with juiciness perception. All measured texture related traits showed that they were all under genetic control with high heritability values. Higher values were obtained for fruits after 2 months storage. These results provide ground for future search of new apple texture QTLs

    Variability of cell wall polysaccharides composition and hemicellulose enzymatic profile in an apple progeny

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    The genetic variability of apple cell walls polysaccharides chemical composition and structure was assessed in a progeny of 141 individuals harvested over 2 years. The variability of the hemicelluloses oligosaccharides released by glucanase was analyzed by MALDI-TOF MS. The genetic contribution was distinguished from harvest year as well as from parental crossing patterns and scab resistance selection. Results showed that harvest year had a major impact on cell wall polysaccharide composition and structure. Within each harvest, genetic effect impact more significantly cell wall polysaccharide chemistry than does reciprocal crossing or early scab selection. Uronic acids, glucose, galactose and xylose contents as well as some glucomannan and xyloglucan structures have a high heritability. This first cell wall chemotyping of an apple progeny opens the way for future searches of genetic markers for the chemical variability of cell wall polysaccharides

    Dye sensitized solar cells as optically random photovoltaic media

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    n order to enhance optical absorption, light trapping by multiple scattering is commonly achieved in dye sensitized solar cells by adding particles of a different sort. Herein we propose a theoretical method to find the structural parameters (particle number density and size) that optimize the conversion efficiency of electrodes of different thicknesses containing spherical inclusions of diverse composition. Our work provides a theoretical framework in which the response of solar cells containing diffuse scattering particles can be rationalized. Optical simulations are performed by combining a Monte Carlo approach with Mie theory, in which the angular distribution of scattered light is accounted for. Several types of scattering centers, such as anatase, gold and silver particles, as well as cavities, are considered and their effect compared. Estimates of photovoltaic performance, insight into the physical mechanisms responsible for the observed enhancements, and guidelines to improve the cell design are provided. We discuss the results in terms of light transport in weakly disordered optical media and find that the observed variations between the optimum scattering configurations attained for different electrode thicknesses can be understood as the result of the randomization of the light propagation direction at different depths within the active layer. A primary conclusion of our study is that photovoltaic performance is optimised when the scattering properties of the film are adjusted so that the distance over which incident photons are randomized is comparable to the thickness of the film. This simple relationship could also be used as a design rule to attain the optimum optical design in other photovoltaic materials.European Union 307081Ministerio de Economía y Competitividad MAT2011-23593, CSD2007-00007Junta de Andalucía FQM3579, FQM524

    Factors associated with mental health outcomes after COVID-19: a 24-month longitudinal follow-up study

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    Objetivo: Investigar la proporción de resultados de salud mental (MHO) y los factores asociados en los supervivientes del COVID-19 durante un periodo de seguimiento de 24 meses. Método: Se realizó un estudio observacional, prospectivo en un hospital universitario de Barranquilla, Colombia, desde el 1 de abril de 2020 hasta el 30 de agosto de 2022. Se reclutó una cohorte de 1565 sobrevivientes de COVID-19 después del alta de los servicios de urgencias (SU), piso de hospitalización (FI) y unidad de cuidados intensivos (UCI) y se les hizo seguimiento durante 24 -meses. La evaluación clínica incluyó escalas de detección de síntomas de ansiedad, depresión, trastorno de estrés postraumático (TEPT) e insomnio. También se recogieron factores sociodemográficos y clínicos para identificar posibles factores asociados. Se realizaron modelos descriptivos, bivariantes y lineales mixtos de efectos aleatorios. Resultados: Se incluyeron un total de 1565 pacientes, de los cuales 785 (50,35%) eran hombres. Se identificó una gran proporción de pacientes con síntomas mentales. Después de 24 meses, las proporciones de síntomas de ansiedad, depresión, TEPT e insomnio seguían siendo elevadas: 16,55%, 21,79%, 35,27% y 23,86%, respectivamente. Los factores sociales, la localización de las estancias hospitalarias, las comorbilidades físicas y la gravedad del COVID-19 se asociaron significativamente con los síntomas de ansiedad, depresión, TEPT e insomnio. Conclusiones: Se han documentado los efectos nocivos de la COVID-19 sobre la salud mental durante 2 años, así como las variables que influyen en estos resultados. Estos resultados deberían ayudar en el desarrollo de iniciativas de salud pública para reducir las tasas de morbilidad en pacientes post-COVID-19. 2023 Los autores.Objective: Investigate the proportion of mental health outcomes (MHOs) and associated factors in COVID-19 survivors during a 24-month follow-up period. Method: An observational, prospective study was performed in a teaching hospital in Barranquilla, Colombia, from April 1, 2020, to August 30, 2022. A cohort of 1565 COVID-19 survivors was recruited after discharge from the emergency room (ER), inpatient floor (IF), and intensive care unit (ICU) services and followed for 24 -months. The clinical assessment included screening scales for symptoms of anxiety, depressive, post-traumatic stress disorder (PTSD), and insomnia. Sociodemographic and clinical factors were also collected to identify possible associated factors. Descriptive, bivariate and mixed random-effect linear models were performed. Results: A total of 1565 patients were included, of whom 785 (50.35%) were men. A large proportion of patients with mental symptoms were identified. After 24-months, the proportions of anxiety, depression, PTSD, and insomnia symptoms remained high at 16.55%, 21.79%, 35.27%, and 23.86%, respectively. Social factors, location of hospital stays, physical comorbidities, and the severity of COVID-19 were significantly associated with anxiety, depression, PTSD, and insomnia symptoms. Conclusions: COVID-19's 2-year deleterious impacts on mental health, as well as the variables influencing these findings, have been documented. These results should aid in the development of public health initiatives to reduce morbidity rates in post-COVID-19 patients. © 2023 The Authors

    Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid

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    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA + LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6 log CFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA + LA. The disinfection efficiency of PAA + LA increased with decreasing pH. Furthermore, PAA + LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA + LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.Ciencias de la Alimentació

    Predicting Visual Overlap of Images Through Interpretable Non-Metric Box Embeddings

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    To what extent are two images picturing the same 3D surfaces? Even when this is a known scene, the answer typically requires an expensive search across scale space, with matching and geometric verification of large sets of local features. This expense is further multiplied when a query image is evaluated against a gallery, e.g. in visual relocalization. While we don't obviate the need for geometric verification, we propose an interpretable image-embedding that cuts the search in scale space to essentially a lookup. Our approach measures the asymmetric relation between two images. The model then learns a scene-specific measure of similarity, from training examples with known 3D visible-surface overlaps. The result is that we can quickly identify, for example, which test image is a close-up version of another, and by what scale factor. Subsequently, local features need only be detected at that scale. We validate our scene-specific model by showing how this embedding yields competitive image-matching results, while being simpler, faster, and also interpretable by humans.Comment: ECCV 202

    Tissue-resident memory CD8⁺ T cells amplify anti-tumor immunity by triggering antigen spreading through dendritic cells

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    Tissue-resident memory CD8⁺ T (Trm) cells mediate potent local innate and adaptive immune responses and play a central role against solid tumors. However, whether Trm cells cross-talk with dendritic cells (DCs) to support anti-tumor immunity remains unclear. Here we show that antigen-specific activation of skin Trm cells leads to maturation and migration to draining lymph nodes of cross-presenting dermal DCs. Tumor rejection mediated by Trm cells triggers the spread of cytotoxic CD8⁺ T cell responses against tumor-derived neo- and self-antigens via dermal DCs. These responses suppress the growth of intradermal tumors and disseminated melanoma lacking the Trm cell-targeted epitope. Moreover, analysis of RNA sequencing data from human melanoma tumors reveals that enrichment of a Trm cell gene signature associates with DC activation and improved survival. This work unveils the ability of Trm cells to amplify the breath of cytotoxic CD8⁺ T cell responses through DCs, thereby strengthening anti-tumor immunity

    Layer-dependence of macroscopic and atomic magnetic correlations in Co/Pd multilayers

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    The development of multilayered materials with engineered magnetic properties compels a deep knowledge of physical properties at the atomic scale. The magnetic anisotropy is a key property in these materials. This work accounts for the magnetic anisotropy energy and its correlation with atomic properties of Co/Pd multilayers with the number of Co/Pd repetitions. Magnetometry measurements confirm stronger perpendicular magnetic anisotropy energies as the number of repetitions increases up to 40. However, the intrinsic anisotropy, related to the Co-Pd orbital hybridization and spin-orbit coupling, saturates at 15 repetitions. This finding is supported by x-ray magnetic circular dichroism analysis that reveals a direct correlation of the atomic Co and Pd orbital magnetic moments and the effective anisotropy of the system. The proximity effect that accounts for the Pd induced magnetization, along with the increasing Co moment, provides a suitable mechanism for the observed anisotropy energy layer dependence

    Matched cohort study on the efficacy of tocilizumab in patients with COVID-19

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    Background: Tocilizumab has been proposed as a treatment for the new disease COVID-19, however, there is not enough scientific evidence to support this treatment. The objective of this study is to analyze whether the use of tocilizumab is associated with respiratory improvement and a shorter time to discharge in patients with COVID-19 and lung involvement. Methods: Observational study on a cohort of 418 patients, admitted to three county hospitals in Catalonia (Spain). Patients admitted consecutively were included and followed until discharge or up to 30 days of admission. A sub-cohort of patients treated with tocilizumab and a sub-cohort of control patients were identified, matched by a large number of risk factors and clinical variables. Sub-cohorts were also matched by the number of other treatments for COVID-19 that patients received. Increment in SAFI (inspired oxygen fraction / saturation) 48 h after the start of treatment, and time to discharge, were the primary outcomes. Mortality, which was a secondary outcome, was analyzed in the total cohort, by using logistic regression models, adjusted by confounders. Results: There were 96 patients treated with tocilizumab. Of them, 22 patients could be matched with an equivalent number of control patients. The increment in SAFI from baseline to 48 h of treatment, was not significantly different between groups (tocilizumab: −0.04; control: 0.09; p = 0.636). Also, no difference in time to discharge was found between the two sub-cohorts (logrank test: p = 0.472). The logistic regression models, did not show an effect of tocilizumab on mortality (OR 0.99; p = 0.990). Conclusions: We did not find a clinical benefit associated with the use tocilizumab, in terms of respiratory function at 48 h of treatment, or time to discharge

    El proyecto "ciencia y comarca" (cico) : una experiencia con 25 años de historia

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    La intención de promover una educación en ciencias sustentada en el propio medio natural no ha pasado de ser un propósito más de las reformas educativas. Las propuestas curriculares no han sido suficientemente precisas en cuanto a la vinculación del aprendizaje al propio entorno, han confundido con frecuencia educación en el medio con educación ambiental, y en ningún caso se han contemplado los requisitos necasarios para implementarla. Los grupos de trabajo, surgidos, como el nuestro, con la aparición de los servicios de perfeccionamiento del profesorado, tratarón de interpretar el espíritu de los objetivos curriculares y llevarlos a la práctica. La descripción de nuestra propuesta y su desarrollo durante los últimos veinticinco años es el objeto de esta comunicación
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